The present invention relates to a plough-share-like mixing tool for a mixing mechanism rotatably mounted in a mixer with a cylindrical mixer container, which mixing tool is arranged on the outer end of a radially running arm fixed on the shaft of the mixing mechanism and brushes the internal wall of the mixer container.
Mixing tools of this type are known, for example from German Auslegeschrift No. 1,051,250. These known plough-share-like mixing tools are designed symmetrically, i.e., have mirror image identical sides, so that they convey the mixed product which they have ploughed through fairly uniformly towards both sides. The mixing tool is generally designed as a closed hollow body and has, in particular, a closed base which revolves tight against a container wall and whose shape is adapted to the shape of the cylindrical container wall. This mixing tool should not only bring about the mixing process but also ensure that as far as is possible no mixed product is deposited on the container wall or that any deposits which may have been formed on the wall are kept as small as possible or even removed from the wall.
It is also known to use so-called half-shovels for brushing the vertical end walls of a mixer container, that is to say half a plough-share-like mixing tool halved in the length-wise direction along its mirror plane, and which therefore has only one edge for mixing and conveying the mixed product on one side, the other side being absent and, accordingly, the arm holding the mixing tool runs along the respective end wall of the mixer container, directly on the wall and keeps it free from, or removes, deposits of mixed product. If necessary, the shovel itself may be dispensed with in such a mixing tool so that an arm extending radially from the shaft of the mixing mechanism to the internal wall of the container, brushes the respective end wall of the mixing container when the shaft of the mixing mechanism runs.
In many cases, and particularly when a pressure other than atmospheric pressure is to prevail in the mixer container during operation, containers with curved ends and in particular mixer containers whose ends are formed by so-called dished boiler ends are used. Owing to the special curved shape of the dished boiler ends, tools of specific contour are necessary for brushing these internal walls. Formerly, when tools were provided mainly in the region of the dished boiler ends, they were designed simply as a type of stripper, that is to say, as tools which have almost no conveying action and only an unsatisfactory mixing action.